Rotating concrete finishing machines currently in use are relatively heavy, often weighing over 65 pounds, are usually difficult to maneuver and are expensive to produce. Because of their bulk and weight distribution, prior devices are awkward to handle and virtually impossible to lift while in operation any more than it would be possible to lift a wheelbarrow by its handles. This makes it hard to clear objects or to place the machine in restricted spaces such as in closets, under stairways or behind pipes. In addition, because of the way they are constructed, it is difficult or impossible to finish the concrete all the way to each wall of a room. Instead, it is considered normal for current equipment to leave a 3″ or 4″ gap of unfinished concrete next to the wall so that the cement worker must put on kneeboards so that he can hand trowel the unfinished area next to the wall around the entire room. In U.S. Pat. No. 2,342,445, which is typical, the troweling blades are spaced centrally 2″ or so from the ring guard 34 as shown in FIG. 2 and in U.S. Pat. No. 2,605,683 the blade 19 is spaced centrally from the guard ring 3 (FIG. 2). Likewise in U.S. Pat. No. D 472,248 the blades are shown spaced centrally from the guard in FIG. 4 and U.S. Pat. No. 6,637,974 provides wall roller guards that keep the blades away from the wall.
In view of these and other deficiencies of the prior art, it is one object of the invention to find a way of building a concrete finishing machine so that while in operation it can clear obstructions such as pipes or door sills and easily get over other objects that are connected to the floor as well as around them while the machine is in operation.
Another more specific object of the invention is to provide a concrete finishing machine that will finish concrete all the way to each wall of a room and can be easily maneuvered around pipes and into small spaces and corners.
Another object of the invention is to provide a concrete finishing machine that will provide a total floor finish without the requirement for hand finishing next to walls and in corners.
Another object of the invention is to provide an improved concrete finishing machine that is smaller and lighter than prior equipment and is able by making possible an operating head with a low profile to get under objects such as stairways, readily maneuvered around pipes, easily lifted manually over objects that project upwardly from the floor and placed in restricted areas such as closets.
A further specific object of the invention is to provide a rotating concrete finishing machine that is balanced in a way that enables it to be easily lifted by hand, is rugged in construction, reliable in operation, can be produced at low cost and has a motive power unit that can be supported by the operator during use.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example but a few of the various forms of the invention within the scope of the appended claims.